The purpose of the research is to identify brain regions primarily involved in the processing of emotions in humans. Emotional processing will be examined in two sensory modalities of stimulation and two modalities of motor expression. The emotions of happiness and sadness have been isolated for this initial study. The effects of interpretation, experience and expression (parallel to receptive and expressive aspects of language) will be determined experimentally, and sex differences will be evaluated. The dependent variable will be regional brain activity, measured by the 133-Xenon clearance technique for quantifying regional cerebral blood flow (rCBF). The study will also create a normative data base for future comparison with clinical populations.